Spark-plug.



c. H. BRASELTONG; F. M. CARROLL.

SPARK' 'PLUG. 1

APPLICATION FILED AUG. 17. 1914.

Patenteci 311116 18, 1918.

2 SHEETSSHEET 1.

C. H. BRASELTON 64 F. M. CARROLL.

SPARK PLUG. APPLICATION FILED AUG. I7. Ham. v

Patented June 18, 1918.

2 SHEETSSHEET 2.

ATTORNEY UniTED STATES PATENT OFFICE.

CHESTER H. BRASELTON AND'FRED M. CARROLL, OF DAYTON, OHIO, ASSIGNORS, BY

MESNE ASSIGNMENTS, T0 WOLVERINE SPARK PLUG COMPANY, INC., A CORPO- BATIGN 013 NEW YORK, (INCORPORATED IN 1916.)

' srnmertne.

Specification of Letters Patent.

Patented June 18, 1918.

To all whom it may concern Be it known that we C-r nsrnn H. BnAsnL- TON and FRED M. CARROLL, citizens of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Spark-Plugs, of which we declare the following to be a full, clear, and exact description.

This invention relates to spark plugs for internal combustion engines and particularly to the means embodied in spark plugs for fastening the electrode carrying insulator in place in the bushing or body portion of the plug. It also has to do with a. novel manner of wiring for the plug and arrangement of a second electrode carried by the insulator.

A main object of this invention is to provide for a quick or convenient removal of the insulator from the bushing in which it is seated and for a quick or convenient replacement therein all without the use of a Wrench or other tool as is usually required.

It is also an object of this invention to use a means for fastening the insulator in place in the bushing which is of a somewhat yielding or-elastic nature so that in service it may yield more or less in places required to take up occurring variations in the different parts as will be present in them when making the plug in quantities. yet at the same time eiiecting a sulliciently strong pressure on the insulator to hold it in an air tight manner against its seat in the bushing so as to prevent escape ofcompressed gases from the cylinder through the plug.

The invention. embodies when its principle is broadly considered, the principle of the spark plug described in application Serial Number 800161, filed November 10th, 1913 by Herman F. Sadgebury, for an invention in spark plugs, but it shows improvements thereover in several respects. for example in the yielding or elastic nature of the insulator fastening means above referred to, in the provision for a preliminary auxiliary adjustment of the fastening means before the same is finally operated to clamp the insulator to its seat, thus to permit a greater range of tolerance in making the different parts and thereby lessen the manufaoturin z cost of the article, and in the design oi" the present 3 which the fastening 71}. ans

for the insulator is securely fastened to the insulator at all times thereby eliminating what would otherwiselic an extra loose part easily misplaceable and lost when the plug is disassembled. The present design is further an improvement over the design of the above mentioned pending application as rewhich is in common use for spark plug in-- sulators.

With the above and other incidental objects in view our invention further consists in various novel details of construction and design which will now appear in a detailed description. of the preferred form of the invention shown in the accompanying drawings which form a part of this application and in which, I

Figure 1 is a view of the completed plug showing it one-half in longitudinal section and one-half in elevation.

Fig. 2 is a perspective view ofthe bushing of the plug. v

Fig. 3 is a view inelevation of the insu lator of Fig. 1 with the fastening member attached.

Fig.4 is a view of the fastening alone. V

Fig. 5 is a sectional view of the fastening member taken on the line aa of Fig. 4.

Fig. 6 is a view of a modified form of fastening member. s

Fig. 7 is a sectional view of this modified form of bail taken on the line F-'F of Fig. 6 looking in the direction of the arrow.

Fig. 8 is a view of a slightly modified form of insulator.

Fig. 9 is a View partly in section, of a modified form of plug in which the fa stening member is not permanently engaged with the insulator but engages the same when in place, only on a shoulder on the insulator.

Fig. 10 is a View of a further modified member form of plug in which the fastening mom-'- ber acts on the insulator through themedium of a separate sleeve, thebushing being partly cut away to show the relative construction of the parts. i

lid

Fig. 11 shows the separate sleeve Fig, 10 with the fastening member-attached.

Fig. 12 shows a plug in which thebushing is omitted, the insulator seating directly in an opening in the engine casino".

In the drawings 1 is the plug bushing ex ternally shouldered at 2 and threaded at 3 for detachable engagement in a threaded opening in the engine casing. The bushing is hollow and is provided with an interior upwardly facing shoulder 41:. The insulator 5'is provided intermediate its ends with an exterior downwardly facing shoulder 6 adapted when the insulator is in place in the bushing, to rest in an air tight manner on; the internal shoulder i of the bushing. The insulator carries a central electrode 7 pro jecting at its lower end from. the insulator and stopping flush at its upper end with the insulator proper. A metallic cap 8 is fast to the upper end of the insulator coverin the same and electrically connecting wit the upper end of the electrode 7. The cap is'provided with a threaded. stud carrying a binding nut 9 serving to securely receive and hold the end of a circuit wire conveying a current of electricity to the plug. The

. insulator may carry but one electrode or it may carry both. In Figs. 1, 3, 8, it) andlf i two electrodes are shown carried by the insulator while in Fig. 9 the insulator appears carrying but one. In this .latter figure a second one can conveniently be aded by merely covering the surface of the upper shoulder on the insulator with a metal band and running the other electrode shown in the other views to electrically connect with said band. In-the views showing both elecbushing through the fastening trodes carried by the insulator the second one is designated by reference character 10 and the spark is of course to jump between the lower ends of the electrodes 7 and 10. it but one electrode is carried by the insulater the other is of course to be carried by the bushing l at its lower as shown at 11 in Fig. 9 and the spark is oi course jump between this electrode 11 the lower end of the central electrode 7. Where the insulator carries both electrodes the second one is preferably electrically connected with the member which is preferably made of metal and when holding the insulator in place in the bushing, is in engagement with the metallic bushing as well as with the second electrode or some conducting material electrically connected with the second electrode, as will all clearly appear from the hereinafter contained description ill the construction in this.

respect.

AS-Stfiilfid. above in the objects provision is made in this invention so that the insulator with its one or two electrodes which it carries, as the case may be, may be conveniently and quickly secured in place bushing and just as quickly and conveniently removably therefrom for such purably 180 degrees apart two slots each having 1 an entrance portion running generally in the direction of the longitudinal axis of the bushing and a second portion running gen orally in a plane at right angles to the axis of the bushing though said second portions are preferably inclined slightly to such plane so as to approach the lower end of the bushing as they extend away from the entrance portions of the slots. In Fig. 2 the entrance portions of the slots are designated 12 and from the lower ends of these which, as stated, are 180 degrees apart, the .cam portions extend around the bushing in the same angular direction and correspondingly downwardly toward the lower end of the bushing for purposes hereinafter appearing. These portions may approach the lower end of the bushing uniformly or they may approach it variably but in either case corresponding portions of the two slots should approac the lower end of the bushing correspondingly. As will be obvious later the second portions of the slots may if desired, be located wholly in a plane at right angles to the axis of the bushing. in the drawings these portions are shown inclined and are numbered 13. So far as the operation of the plug is concerned it is only necessary that the upper surfaces of these cam portions of the slotsshould be downwardly inclined as it will be obvious from later description of the operation that only the up per surfaces of these portions of the slots are engaged with the fastening member when fastening the insulator in the bushingby the latter.

The above mentioned slots in the bushing are, as stated, for coiiperation with the fastoning member which is used to fasten the insulator in the bushing. The form of fastening member shown in the assembled plugs of the drawings, is shown in elevation in Fig. i and in section in Fig. 5. The fastening member inijthis form is shown made from a wire or rod of circular cross section, bent first into U shape and then having its ends turned inwardly'as shown. In the drawings the main part of this fastening member is designated 1% and its inwardly turned ends 15. Portions of the alined inwardly bent portions 153 are then knocked oil center correspondingly taking a separate alinement than that of the outer por- "an angle of about 51:5 degrees to the plane in tions 15, and being charactegized in the drawings 16, these almed portions 16 being connected with the almed portions 15 by short connecting portions 17. From this axis of the portions 15 in the plane of the main portion 14 of said member, but have knocked said. portions 16 off in a plane at which the main portion 14 extends from the .tenin I of elliptical cross section andwithout nialrinwardly turned portions 15. The reason for'this relationship will better appear in a description of the operation of the plug.

-The form of fastening member may be varied and to illustrate we have shown another form in Figs. 6 and 7 in which'the fastening member is formed from spring steel stock of elliptical cross section bent into U shape and its ends merely nrned inwardly in alinement and at their points where inwardly turned merely given a twist of i5 degrees so that the major axis of the in Wardly turned portions wlll be at such angle of 41:5 degrees from the direction of the main portion 14. The main portion of this fastening member is bent U shapefii the direction of the major axis of its elliptical cross section. For all practical purposes a fasmember so made from spring steel ing the additional bend or set off "1:6 as in short preferably the form of Figs. 4 and 5, operates similarly for the purposes of our plug and a fastening member of either form will sui'licc. 'lhe inwardly turned portions of the fastening member made from the elliptical stock and shown in Figs. 6 and 7 are designated by reference character 15.

The insulator of our plug is shown designed in different ways. In the preferred form shown in Figs. 1 and 3 it is provided exteriorly and above the downwardly facing shoulder with a peripheral turned away portion or groove 18 preferably extending completely around the insulator. At the deepest portion ofv this groove there are located diametrically opposite transversely extending holes 19 to the bottom of one of which preferably runs the.

second electrode 10 as shown in Figs. land 3. While these may be om1tted, we preferably line the interior of the holes 19 with metal sleeves 20 which may be cemented in place and. these sleeves serve to receive directly pressure from the fastening member and communicate it to the material of the insulator resulting in more of a distribution of the pressure from the fastening member over a greater locality of the insulating-material with the idea of decreasing the danger of breakage of the insulator by reason of the localization of all the pressure of the fastening member on the insulator in substantially two localities. While the use of the sleeves 20 may iirsome cases with some grades of insulating material, improve the service of the plug they are in many cases not at all necessary or advisable. Where they are used however, the upper end of the second electrode 10 may contact with one of these sleeves as shown in Figs. 1 and 3. In Fig. 8 there is shown a design in which these sleeves 20 are omitted and in this form in order not to weaken the insulator directly beneath either of the holes 19, the second electrode 10 does not run up to the bottom of its adjacent hole 19 but up at one side of the hole so that it may pierce the hole at one side and there make electrical connection with the metallic fastening member when the latter is holding the insulator in place in the bushing. In this view the holes are numbered 19 and the second electrode 10.

In the forms of Figs. 1, 3, and 8 we preferably permanently attach the fastening member to the insulator, that is so it re mains fast to the insulator in all use of the plug though it may be conveniently removed therefrom if desired. As stated above, the fastening member is preferably formed from spring steel material and when so constructed the fastening member may be readily sprung to locate its ends in the holes 19 of the'insulater of Fig. 8 or in the interior of the sleeves 20 of the form of insulator of l and 3 and when so located in these holes or sleeves the action of the spring material will prevent any undesired removal of the fastening member from the insulator. Whilehaving also another function, the peripheral groove 18 in the insulators are useful in. decreasing the amount of springing the fastening memher would otherwise have to do in putting it in place on the insulator as it is in some cases desirable that the ends of the fastening member project into the insulator suiii ciently to meet the second electrode 10 which in some cases it is most desirable to extend parallel of the axis of the insulator and not be deflected outwardly as shown in the form of Fig. 10. Sln cases where the second electrode extends parallel to the axis of the insulator andwherea rather wide shoulder 6 is used on the insulator, if the groove 18 or. some other form of recess is not formed adjacent the holes 19, it would in some cases be hard to get the fastening member to ill me es will give some length of the mste'rimil'oi the festening member between. the point of engsgement With the bushing end the point of engagement of with the iusulutor, thus providing for desirable spring in the fasten ing member between these points to aid in taking up insccurucies in the manufacture of the difierent parts Without siil'ecting the operation of securing insulator in place in the bushing f rmly. l fith desirable spring in the 1 member the insulw tor is held against its seat with u somewhut yielding; though firm pressure and this We find an sdvsntuge with our spsrlr plug in decreasing the breulzege f insulators When hot from use over when they are held,

downwardly against their seat by s more positive fastening means, particularly when using no gaskets between the shoulder 6 on the insulator and the shoulder l on the bush; ing but instead ground or otherwise smoothed surfaces on these shoulders as We show in. all the forms of the drawings.

The plug Figs. 1 to 3 is assembled otter the bushing l is screwed into place in the engine casing if by the in. sulutor with the fustening member attached, as shown in Fig. 3 and the main portion of the fa suing. member turned up along the side of the insulator, Placing the insulator down endwise into the hollow bushing and with the portions 15 of the fostening member passing downwardly in entrance portions 12 of the diametrically opposite slots in the top of the bushin After the insulator is sutliciently lowered for the portions 15 of the fastening member to reach the substantially horizontal por- 'tions of these slots, the insulator with the fastening member is turned to carry the por tions of the fastening member into the horizontal portions of slots end, de sired, until these portions 15 engage the upper surfaces of these horizontal slots when the shoulder 6 of the insulator is resting on the internal shoulder 4 in the bushing The insulator may then be securely forced. against the seat in the bushing by merely swinging the main portion 14 of the fastening menn her down about its bearings in the bushing to about 4.5 degrees from 2. depending position in. slinement with the axis of the plug when the insulator Will be firmly and se surely held against its seat in the bushing, for by such swinging action the eccentricity o c portions 15 of the fastening member ngege in the slots lIl the bushing, to ens it which Work. the hoes in.

iere the fastening member eccentric pressure on the insulator.

mic

the insulator causes the insulator to be forcibly engaged against its se'etfin the bushing to Wl'uch position it will be held by the fastening member when the fastening member is so swung down, by reason o the portions it then being beneslfth the portions 15 or so nearly so that uleieis. no force noting in the proper direction on these parts to overcome the existing-friction or inertia, end csuse the fastening member to be syvung buck upwardly to its original position in Which itwss inserted, and relieve the cam or In this notion just described, the resilient nature of the fastening membercomes Well into play though it may be dispensed with if the parts ere suiiiciently accurate in construction. We prefer to use the fastening member mode from spring meteriul but when so constructed it is perfectly practical to omit any inclinetion in the upper surfaces of the horizontel portions of the slots in the bushing as all necessary tolerance in the manufacturing of the various parts can Well be taken care of by the elasticity in the fastening member.

ifll

Should We omit the elasticity in the fssten- I ing member due to the use of spring stock We preter to use the inclines on the upper surfaces of the horizontal portions of the slots in the bushing for with them provided, en adjustment of the parts can be efilectcd by rotating the insulator until the portions oil"- the fastening member engages these surfaces whereupon the fastening member may then be swung down with e suretyin.

the complete seating action of the insulator! against its seat which surety might not elWo-ys exist it the parts "were not always made sccurote Without any substantial closticity in the fastening member'or any pre liminery adjustment possible by means of the inclined surfaces on the bushing slots or some equivalent. If there is substantially no spring" in the fastening member the cfi'ective throw of the eccentrics on the fastening member would have to be considerably less.

Also it will be observed that by the use of spring materiel in the testening member that us the portions of it inside of the bushbeorings bend or yield as the fastening member is swung down the eccentricity of the fastening member will accordingly decrease thus enhancing the leverage of the fastening member over What it would otherwise be for as it springs the eccentricity of its bearings accordingly decreases with a resultent increase-magnification of the me chenicol advantage of the fastening member as or pressure applying means. It is of course true that the mechanical advantage would gradually increase with the fastening member non-elastic but by being also yielding end of I trio construction the increase mech edventsge is greatly augfastening member remains attached to the.

To remove the insulator from the bushing the reverse of the above operation is merely used and it will be seen that this can readily be done without the use of any wrench or tool by merely catching the fastening memher with the fingers and pullin it upward, then giving the insulator a slig t turn, and removing it axially'of the bushing. The operation of assembling the plug is also done similarly without a wrench or tool. The

insulator in this form, when the plug is disassembled and is not liable of being misplaced and lost. It will be seen that when the plug is assembled the fastening member is in electrical connection withthe second electrode either by engaging the upper end of it directly as in the form of insulator of Fig. 8, or by engaging the sleeve 20 which engages the electrode in the form of Figs. 1 and 3. In either form the fastening member by engaging the bushing conducts the return current to the latter from which it returns to the battery or magneto through the engine as is common. The wire connected to the upper end of the other electrode 7 leads to the other side of the battery or magneto in the usual manner. If but one electrode is to be carried by the insulator the wire 10 ,in the latter is omitted and the other electrode is carried by the lower end of the bushing in the usual way, as shown in connection with Fig. 9.

The operation of the fastening member is substantially the same when the fastening member is formed from elliptical stock as shown in Figs. 6 and 7. The variable diameter of the inwardly turned portions which bear on the insulator and the bearings of the bushing provides a cam action which, the fastening member is swung down, cams the insulator firmly against its seat in the bushing. A similar springing action takes place when the member is made from spring stock and a similar augmentation of the mechanical advantage of the fas-' insulator out is a. separate element removable and replaceable as such. The insulator is shown i'zarrying but the one central electrode 7 and the other electrode 10 projects fron'i inc lower end of the bushing in the usual way. Otherwise the bushing the same as the forms heretofore described. The insulator is minus the transverse holes for the fastening member and the peripheral groove, but it is provided with an upwardly facing shoulder '21'the up er surface of which corresponds to the ottom of the transverse holes in the forms just described. In assembling this plug the insulator is placed in position in the bushing with its lower facing shoulder f3 resting on the up wardly facing shoulder -l in the bushing. The fastening member is then lowered in place through the slots 12; then turned slightly axially to engage'the portions 15 in other forms. Reversal of the operation releases the insulator and frees the fastening member for removal after which removal the insulator may be freely lifted out. if desired a metal band may rest on the shoulder 2-1 permanently and.if it is desired that the insulator of this form carry both electrodes the second one may extend downward from this band to the lower end of the insulator, the band electrically connecting the second electrode with the fastening member.

Fig. 10 shows a still different form in which the fastening member is carried permanently by the insulator as with the form of Figs. 1 and 3 but it is so carried directly by a metal band 22 resting on a shoulder on the insulator and held in place on the insulator by being crimped inwardly at 2 beneath a peripheral ridge on the insulator. For the purpose of this crimping the upper end of the metal band is provided with a thin fin 25. This band is provided with diametrically opposite holes 26 for receiving the ends of the fastening member as do the holes 19 of the form of F 1 3. These holes are counterhored at 2'? ix) a length of the fastening member between the bushing and the point of engagement with the band for the purpose making the me1nher more yielding, as has been heretofore noted to be desirable in connection with the description of the other forms. The second electrode in. this form may run to the shoulder 21 on the insulator and there contact with the band which engages the fast-ening member 1 whieh electrically connects with the bushing when the plug is assembled. this term the operation and action the same as wiih the form of Figs. 1 and 3 the hand and fastening member remaining attached to the insulator. the band merely reinforcing the insulator mechanically against the action of the fastening member in clamping the insulator in place,

. Very under different circui'nstances end ra-r) upstanding ears or hooks 28 uncler which the portions 15 of the fastening member may engage. Then by lacing the insoletor against its seat, turninp" so that the factoning member portions i5 will come beneath ihe hooks 29 end subsequenilyswinging-the fastening member 14- the insuieior will he forced. firmly against its and held as before. To remove the insulator the reversel of this '0 creation is cerrieci out. The fastening Inem er may" or not lie pee inanently attached to ilie insulator this manner cit" using our insoieaor as i one other forms. It is nec ssery iioweve so loceie the cams or eccentric poriions on fastening" member to usecl in this i that the insulator- "will lee forced iao iis sec-,4, Toy the time the inein portion oi the fissioning member Will engage the engine oesing, as the insulator in the form shown Without the bushing will not .be cerrieci soliigh away from the enfine casing; Whereiiie bushing is used. ii; is preferable that the insole-cor be properly fesienerl "no i'is soot in the bushing when the main or henclle tion of the fastening" member is iie about 45 ciegrees from o veriicel crop from its bearings in ping, yei;

obvious that the offset oi the eccentrics i location of the efi eciive cem portion con be made and locetecl es desirecl to suit the circumstences'encl conciitions under which iiie plug is to "be usecl which conditions niey sometimes very in ,clifiereni; engines in- Whicliii; is desired to use the pings We have shown no gasket between the shoulder 6 of 'ie insuleior and siiooltier i of the bushing as We to use merely ground or other smoothed joint here but it is to be understood that instead of o ground joint e gasket of any suiie uie form may be used this not affecting the poizenizeole principies of our plug. Other numerous elm vious changes in like designs of our ping" which e hove shown; merely for illusireiive purposes, will no doubt occui: to those skilled in insert enci We do confine our yrotec tion to the details oi? ciesign shown except as oequirecl by the scope of the appended. claims. L

v Homing CiSSCElbSC our inve; claim as our invention encl demo I by Letters Patent is:

1. In e spark plug; for internal combustion fosienine' member is i'oizeieii about leer liming e plnre WW v coi remorse 2, line spark plug foi internal combustion engine's the combination of e bushing; electrocle carrying insulator adapted to removebiy iherein; entl a fastening member having elined inwardly turned ends e portion oi said ends being ieriher from ihe axis rotation of the fastening member ialien. ere portions whereby when the oi: cine in ercily iuinecl encls h poriions' in cooperation with the bushing and the insoieior the insulator will be forced. to

in iiie Touching.

nos, iiie combination of e bushing; en

fiificiliffilo carrying insulator edaptecl to re- .ovebiy cocci/herein; and a fastening niem- W opposed projections for foaming or io its seat in the bushing when member is rotated. I

sick plug for internal combustion engines, the combination of a bushing; an elcciroe cei'rying insulator adapted to removebly sec-ii therein; and e fesiening memloer having plurality of projections 6X- iendiog portions oi the ins'uietor c isp l the fastening member is robeering surfaces on the bushing cmi 5 "1 cc on ertis ei; an angle to the longi i:- riinei axis the plug; to force the in.- egeinsc'iis seat in the bushing.

5; in iii-spark plug for internal combustion engines, the combination of a bushing; an elec'irode carrying insulator adopted to removeoiy see-1b therein; snrl e fastening memher having e plureliiy of projections e2;- izening over portions of the insulator ec iepteci .121 the :festening; member is romixed about plurality of diametrically opposite bearing surfaces on the bushing, anal about enexis an angle to the longitudinal axis of the plug, to force the insulator against its sees in the bushing .6. in a spark plug for internal combustion- @lGCl'JEFGClE carrying insulator. colapted to removeloly seoi:

.132 of portions Ior enoliizy oi ;oei'iplnerslly seperetecl fee bushing, and having o plus-slit L ions oriented to pro ec'u} over i -3 of peripherally seperziieci poo; es of the insulator, whereby when the i esie'emg is retained with its corresponcling' portions in engagement with the gaging a, pier loeering sin bearing siiri'eces'on ilne bushing ancl plug ior internal combustion coercing 'encl a fostenine' memother mentioned portions projecting over the insulator, the insulator will be forced against its seat in the bushing. 7.111 a spark plug for internal combustio engines, the combination of a bushing; an electrode carrying insulator adapted to removably seat therein; and a fastening mem her having a lurality of portions tor engaging a plum ity of peripherally separated bearing surfaces on the bushing, and having a plurality of portions adapted to project over a plurality of peripherally separated portions of the insulator, whereby when the fastening member is rotated about an axis at an angle to the longitudinalaxis of the plug, with its corresponding portions in engagement with the bearing surfaces on the bushing and with its other mentioned portions projectin over the insulator, the insulator will be orced against its seat in the bushing.

8. In a spark pin for internal combustion engines,the com ination of a bushing; an electrode carrying insulator adapted to removably. seat therein; and a fastening member having separated portions adapted to project between-the bushing and insulator at peripherally separated points of the plug,

- said portions constructed so that rotation of the lastening member about an axis at an angle to the longitudinal axis of the plug will cause relative movement between the insulator and bushing to force the former against its seat in the latter.

9 In a spark plug for internal combustion engines, the combination of a bushing; an

electrode carrying insulator adapted to seat therein; and a fastening member adapted to straddle the plug and having separated portions adapted to project between the bushing and insulator at peripherally separated points of the plug, said portions constructed so that rotation of the fastening member about an axis passing through the separated portions of the fastening member will re ative movement between the insulator and bushing the its seat in the latter.

10. in spark plu" for internal coinbustion engines, the com ination of bushing; an electrode carrying insulator adapted to removably seat therein; and a fastening member adapted to'struddle the bushing.

' ii. In. spark plug for: internal combustion engines the combination of a bushing;

an electrode carrying insulator adapted to removably seat therein; and a iastenin'g member adapted to straddle the insulator Y 12. In a spark plug for internal combus tion engines, the combination. of a bushing provided with an internal seat and peripherally separated L shaped slots at its upper end; an electrode carrying insulator adapted to removably seat therein against said internal seat; and a fastening member adapted to straddle the bushing and having separated portions adapted to pass down through v the vertical portions of the L shaped slots and into the horizontal portions of the same and to extend over peripherally separated portions of the insulator, the construction of the separated portions of the fastening member being such that rotation of the'fastoning member about an axis passing through its separated portions when said member is in. place in the horizontal portions of the slots, will cause relative movement between the insulator and the bushing and cause the former to be forced against its seat in the latter.

13. In a spark plug for internal combustion engines, the combination of a hollow bushing having an internal seat ,and L shaped slots at its upper end; an electrode carrying insulator adapted to removably seat therein; and a fastening member straddling the insulator and rotatively carried by latter at a plurality of peripherally separated. points and adapted to detachably engage L1 the L shaped slots in the bushing, the construction of the fastening member being such that rotation of the fastening membe? about its connections With. the insulator when the latter in place in the bushing and the fastening member in engagement with the horizontal portions of the L shaped slots will cause relative movement between the insulator and the bushing so as to force the former against its seat in the latter.

' 14. In a spark plug for internal combustion engines, the combination. of a, hollow busl'iing having an internal seat and L shaped slots opening at one end of the bushing; an electrode carrying insulator adapted to removably seat against the seat in the bushing; and a fastening member adapted to be removably placed in the L shaped slots with a portion projecting over a portion of the insulator and so constructed that when rotated When in such position, about an axis tion engines, the combination of a hollow lit;

ti l

bushing having an internal seat and provided with peripherally separated bearing surfaces, points of. which are great 1' distances from said seat than are other points; an electrode carrying insulator adapted to be removably seated in said bushing; and a fastening member provided with inwardly turned ends, portions of which are adapted to bear upon the said bearing surfaces in the.

bushing and other portions of which are adapted to project over and bear upon the insulator to force the latter to its seat in the bushing when the fastening means is rotated about the inwardly turned ends.

16. In a spark plug for internal comhus tion engines, the combination of a bushing having internal seat and peripherally senarated slots open at their upper ends and forming inclined bearing surfaces points of which are at greater distances ire-m seat than are other points; an electrode ca rying insulator adapted to removably seat in the bushing; and a fastening member provided with inwardly turned ends rotatable about an axis at right angles to the axis of the insulator, portions of which ends are adapted to hear upward on such bearing surfaces on the bushing and other portions which are adapted to project over and hear downwardly on the insulator to force the latter to its seat in the bushing in a spark plug for internal combustion engines, the combination of a bushin having peripherally separated L-shape slots at its upper end, the upper surface of the horizontal leg of said slot being inclined downwardly from the Vertical leg to allow for the vertical adjustn'ient of a fastening member; electrode carrying insulator adapted to remo'vahly seat in said "u shing; and a memher having" inwardly turned ends to pass downwardly through the vertical. portions of the slots into the horizontal. portions and adapted to bear upwardly on said inclined portions of said slots and downwardly on peripherally separated portions of the insulator so that when the fastening member is'rotated about the axis oi said ends the insulator is forced against its seat in the l'JUSlllIW.

18. in spark plug; for internal combustion engines, the combination of a bushing;

an. electrode carrying insulator adapted to removably seat therein; and a yielding tastening memher having; separated portions adapted o project between the bushing and tor at peripherally separa 1g, said nortion so ed tho?- rotation of the fastening member all t an aXisa-t an angle to the longitudinal axis t the plug will cause relative movement between the insulator and bushing to force the former against its seat in the latter.

19. in. a spark plug; for internal combustion engines, the combination of a member having an opening to receive a spark plug insulator; an electrode carrying insulator adapted to removahly seat therein; and a fastening member having separated portions adapted to project between the first mentioned member andinsulator at peripherally separated points of the latter, said portions constructed so that rotation of the fastening ineinl'oer about an axis at an angle to the longitudinal. axis of the insulator will cause relative movement between the insulator and "first mentioned member to force the former against its seat in latter.

20. in a sparlr plug forinternal comhus tion engines,-the combination of a bushing having" peripherally separated hearings and an internal seat; an electrode carrying insulator having a horizontal groove extending about'its periphery and adapted/to removably seat in the bushing and a fastening member having in'w rdly turned ends adapted to extend throngs. the hearings in the bushing and to enga o hearing holes extending inwardly of tlie insulator from the depth or" said peripheral groove, said fasten ing member constructed so, that rotation oil it when the parts are assemhled will cause the insulator to be foroetl against its in the bushing.

21. An insulator ".for internal combustion engines having diametrically disposed bearings with the ends of a fastening morn-- her mounted therein, an electrode'passing from one or more oi said hearings to the end of tne insulator forming one spark terminal, and a second electrode extending longitudi nally through the insulator and forming another sparlrterminal.

9:52. lln a sparlr plug for internal comhus tion engines, the combination with an electrode carrying insulator, oi a hush?" ins; hearing openings and a set for sulator, and a fastening member liar Wardly turned yielding ends cooperating till Hill

with the bearing openings and the insulator hold the sore against the-seat in the bush- 24. In a spark plug for internal c0mbustion engines, the combination with an electrode carrying insulator, of a bushing having diametrically opposite bearing openings and an internal seat for the insulator, and a fastening member having inwardly turned ends rotatable in the aforesaid bearings and formed to cooperate with the insulator to yielding'iy hold the insulator against its seat the-hashing when the fastening member lo movedv to a certain position. Y Y 7". a spark plug for internal combustion engines the combination of'a fixml men'iher having a seat and aniopening, an eleotrorie carrying insulator adapted'to pass into the opening and against the seat, and a single manipulatively operable yielding pressure applying element for forcing the insulator against itsseat in the fixed member and hQlding-it there in opposition to pressure el ierteel from the engine chamber when n e plug is use in the same. I a

A plug comprising a fixed mom having-an opening and a Seat for an inan electrode carrying insulator arlaptecl to into the opening and against i a me seat,

rsei in the insulator, and means wheieoy t iasteni g member may isomer.

ually opera eel to exert a yielziing pressure on the insulator to force the same firmly ar nst its seat in the fixed member.

iris spark plug the combination of hashing, an electrode carrying insulator adapted to seat therein, and rotatable yielding pressure applying means adapted to rotate about an axis at an angle to the longi; turiinal axis the-insulator in cooperation with theinsu'iator and bushing, to force the tor against its seat in the bushing. 28. plug the combination of a hushin an electrode carrying insulator adapted seat therein, and a rotatable yielding fasteiiing member for foreiug' the insulator against the seat in the bushing fastening member is rotated when v u M13 in eoopo '21 plug, the combination 0r electrode earryinginsulator to in connection therewith, and a resiiient member rotatahly operating" with the insulator and bushing about an axis at an angle to the longitudinal axis oi the insulator, said axis being on a line that will pass through the projected trausverse area of the insulator, said resilient member serving when rotated to force the insulator against its seat.

341 In a spark plug, a bushing, an electrode (arryiug insulator adapted to seat in the bushing, and a crank like resilient memher rotatahly engaging with the bushing member atlapteci r1 fastening member disposed ration with the insulator and hush bushing ancl toholri ii} there h}?v reason er the crank like member assumzug'a Substantially dead center reiationship hetween 70 the insulator anal hushiiugv 31. Ina spark plug a hushi ig member,

an insulator carrying an electrode and adapted to therein, anti a resilient member rotatable about an axis an angle 78 to the axis of othe' embers ar ful eruming against mentioned members anal aeti. other suhstaritiaii iming" 4 oteti lines of acti. c'iose 8K3 tothe fulcrum re J moment of force tent" her through riemhersru frictional K'QEHSMIYiQ-ft. $5

tatahle memhen troiie earryiiig is there-in, and a graduaily increas the insulator 33. In a later adapterl s an electrorle, ii ro' ital attaeha'oie therewith i 211?} fasteu ally oi? the member in s 'astening so about i axis of the v has corbushing, said, yieldirig limit gaging the insulator and bushing and being manually manipulative to apply a yielding pressure on the same.

37. In a spark plug, the combination of a relatively fixed member; an electrode carrying insulator adapted to removably seat therein; and an element carried by SLld'l11- sulator and. movable therewith into cooperative relationship With. said fixed member; and adapted to be rotated about an axis transverse tothe axis of the insulator to apply pressure to lock it to its seat.

38. In a spark plug, the combination of a relatively fixed member, an element including an electrode carrying insulator adapted to relnovably seat therein, and a single member rotatable about an axis transverse to the axis of the insulator to apply a yielding pressure from said element to the fixed member to lock said element in its seat.

39. In a spark plug, the combination of a relatively fixed member; an electrode carrying insulator adapted to removably seat therein; and an element fulcruming on a bearing surface and acting on said insulator to apply pressure to force it to its seat, provision being made whereby the distance of saidbearing surface from said seat may be varied.

40. In a s ark plug, the combination of a relatively "xed member, an electrode carrying insulator adapted to removably seat therein and an element fulcruming on a bearing-surface and extending over a porition of the insulator, said element being adapted to be actuated so asto apply pres sure to said insulator to force it to its seat, provision being made whereby the distance of said bearing surface from said seat may be varied.

41. As an article of manufacture, an electrode carrying insulator for spark plugs adapted to seat in a bushing and provided with a fastening member yieldingly engaging the insulator so as to be removable therefrom, said fastening member being adapted to lock the insulator to its seat in the bush- CHESTER H. BRASELTON. FRED M. CARROLL.

1 Witnesses:

MARGARET HORAN, JOHN J. Gn'r'rrnes. 

